Not exactly an answer to your question, but we started keeping track of every funding source that we'd heard of or have contact to in our intranet wiki. After a couple months of just keeping your ears open and taking notes you end up with a pretty long list.

That said, just repeating our list wouldn't do you a lot of good; usually you're looking for people that are either in your area or that you have at least some distant connection to. Think you don't have connections? Yeah, so did we. Then we started paying closer attention over a period of time and realized we had quite a few.